Epitaxial growth of nonpolar ZnO on MgO (1 0 0) substrate by molecular beam epitaxy

Nonpolar (1 0 1̄ 0)-oriented ZnO was grown epitaxially on (1 0 0)MgO substrate by plasma-assisted molecular beam epitaxy at a high substrate temperature of 600 °C. The epilayer was composed of four variant domains which have an orientation relationship with the substrate as: (1 0 1̄ 0)ZnO//(1 0 0)MgO and <1 2̄ 1 3̄>ZnO∼//<0 1 1>MgO with a ±1.5° deviation. By introducing a Zn0.4Mg0.6O buffer layer, the lattice mismatch was eliminated almost completely based on the extended coincidence lattice model. The crystal quality is therefore improved and the epilayer shows good photoluminescence characteristics.

► Nonpolar (1 0 1̄ 0)-oriented ZnO was grown epitaxially on (1 0 0)MgO substrate by MBE. ► The epilayer was composed of four variant domains. ► The crystal quality was improved by introducing a Zn0.4Mg0.6O buffer layer.